Medical Applications

Human Bodies: The Harshest Environment



The human body is a masterpiece in the eyes of engineers, as it’s designed to withstand soaring temperatures, biting winds and exposure to water, abrasions and punishing exercise. The human body accommodates our pursuit of adventure and our desire to survive ever-changing climates and environmental vacillations.

Human endeavors continue to amaze, no matter who the risk-takers are—whether ultramarathon runners, multi-mountain climbers, or deep-sea divers working on oil rigs. And through the human mind, we have invented technology to support our every move, save lives, and monitor our moment by moment physical conditions using what we know as wearables.

In this article, we look at how wearables have had to endure the rigors that we put our bodies through and how the designs have been adapted to ensure that wherever we want to go, or need to go, our technology can be right there with us.

History of Wearable Technology

Although technology has accelerated over the past two decades, the progression of wearable technology begins a lot further back than you might think with the invention of the eyeglass in 1286. Later, the Victorians, master inventors themselves, designed an air-conditioned top hat in the 1800s and an electrically lit dress in 1890. But not until this current millennium has wearable technology really come of age.

Philips and Levi Strauss & Co. collaborated in 2000 to create the “ICD+,” a jacket designed with an integral, wired harness that connects a range of portable electronic devices. A central control module (CCM) connected all the devices to allow the wearer to switch between the phone, the MPEG Audio Layer 3 (MP3) player, and the headphones to control their separate functions. The jacket had to withstand swings in temperature from the inside during body sweats to provide a cooling effect and from the outside during weather vacillations, so the designers could ensure that the product was both functional and fashionable. Although it’s unlikely anyone marketed the product to be worn up Everest.

Now, wearables are ubiquitous, with a forecast of more than 170 million wristwatch devices to be sold in 2020. And each time we strap a Fitbit to our wrists, or put on our Apple watch, we’re also asking that technology to go where we go, to withstand what we do, and to perform in places that were historically impossible for humans and electrical engineering to withstand. Designers not only have to make sure their equipment works but that it works in environments that are extreme.

An Arid Landscape

Not a week passes without the news reporting an epic account of a human challenge. Nowhere on the planet is more punishing than being in extreme heat, or extreme cold. California’s Death Valley is officially the hottest place in the world, having recorded a temperature of 56.7°C in 1913, which is beyond the limits of human survival. Today, the area regularly records temperatures of 47°C in the height of the summer. So it’s mind-blowing that we humans decided to challenge ourselves to run the Badwater Ultramarathon (billed as “the world’s toughest race”) in this very area. This 217-kilometer course sees very few finishers, and its fastest recorded runner completed the course in 35 hours. While there have been amazingly no fatalities on the course throughout its 30-years of competitions, it is still seen as one of the ultimate tests of human endurance and survival.

Those runners who take on the course are supported by a crew that gives water and medical aid. Not only does a runner’s body have to survive this extreme challenge, but the technology that is worn does too. Sweat, sand, pressure, force, and heat combined give manufacturers the ultimate environment to test wearable technology. Likewise, scientists use the participants as research objects to learn the limits of human endurance—such as in a 2008 study that observed the athletes’ water turnover.

From an industrial design aspect, the challenge is to maintain a wearable’s form and function, allowing it to be fit for its purpose without too much weight, bulk, or complex user instructions. Even for tasks as simple as a step tracker, the engineer must ensure that the screen can be read in bright sunlight, that the strap can’t erode byway of dirt particles, and that the buttons still work through a layer of sweat and grime. A complex electronic wearable needs to be rugged enough to prevent dust and fluid ingresses into its components, all without hindering an athlete’s focus.

The Daily Grind

Of course, it’s not just ultrarunners who put their bodies and devices through stress. People wearing wearables during their daily commute, taking 10,000 steps, and going about their day in the proximity of their fellow man all combine to put pressure on their bodies and their technologies.

Think about how we wash dishes daily wearing a Fitbit or wash our hands once we’ve been to the restroom. We splash our hands with water multiple times a day, which engineers are aware of, and thus, try to create a level of water resistance even in products that don’t claim to be completely waterproof.

Our fragrances, aftershaves, hand creams, and cosmetics can cause a buildup of dirt that can affect a wearable’s sensors. Reaching into cupboards, picking up children, and vacuuming our homes can cause us to knock our wrists, giving our wearables quite a workout. When we play sports, and sweat our way through a game of tennis or a BODYPUMP class, we can see that a fitness tracker has to be robust and enduring to cope with the way we live our lives. Considering that most fitness trackers now include heart rate monitors, keeping a photodiode detector and light emitting diode (LED) assembly close to the body and free of dirt and sweat is important, which is just one of the many micro-challenges that engineers face.

Our Bodies are Extreme Machines

Those who work in extreme environments rely on technology to stay safe and to monitor their health. Air force pilots, deep-sea divers, and scientists working in Alaska employ specialized equipment to allow their bodies to survive in these extremes: For example, pilots experience acceleration and g-force daily, which are factors that wearables can monitor the physical effects of.

The National Aeronautics and Space Administration (NASA) and military researchers know exactly how much acceleration our organs can tolerate. They discovered that 14g’s of lateral acceleration is unfortunately too much for the inside of the body to cope with. These experts test extremes to determine the limits of human endurance.

For example, as normal air travelers, we still expect our bodies and therefore our technologies to cope with changes in pressure, temperature, and position for several hours—allowing us to step off a plane in New York City, New York, with our technology working as well as it did when we boarded San Francisco, California.

While it’s been proven that most humans will suffer from hyperthermia (overheating of the body) and die after just ten minutes in extreme humidity or 60°C heat, death by cold is harder to delimit. A person usually expires when their body temperature drops to -21°C, but how long it takes to reach this point depends on a few factors, like whether the person is accustomed to very cold temperatures and whether hibernation sets in.

Those of us living and working in the coldest towns—such as Fairbanks, Alaska—have developed coping mechanisms and essential equipment to live and work. With a minimum average temperature of -27°C, the Fairbanks climate gives the human body and technology a challenging and hostile environment. Electronics in such climates can struggle in the colder temperatures: For example, a Fitbit’s operating instructions state that the wearable’s minimum working temperature is -20°F. However, because it’s worn close to the body, its own temperature is kept warmer than the prevailing outside weather.

To allow people to work and play in these extreme conditions, engineers have designed a series of sensors that monitor the temperature of the wearer, alerting the person to any dangerous changes. These sensors have been designed to work in the harshest of environments to help wearable users actively keep their feet, bodies, hands, and heads warm and protected.

In the mind of an electronics engineer, for these sensors to thrive, even a battery design for a wearable needs a customization to cope in these extreme temperatures. Considering some batteries stop working below -30°C and most LED displays also have a specific operating temperature range, both of these components are things engineers need to be mindful of. As we humans strive to work in ever more challenging conditions, the engineers that design our equipment must stay in sync with this progression.

There are also consumer variants of these components including battery-operated warming clothes for hikers and mountain climbers that ensure their comfort and safety during adventures. However, these excursionists will need to transport multiple batteries to keep the warmth going, but this extra equipment may be a burden if lightweight travel is a must! And it’s important after the trip, that an adventurist doesn’t absent-mindedly put all the technology in the laundry. This mishap is something the manufacturers see on a regular basis, and the Internet is full of tips for how to restore your fitness tracker, smartphone, or Bluetooth headset after they have accidentally taken a bath.

We humans don’t seem to be showing any signs of slowing down in our pursuit of adventure nor in our love of conquering some of the most inhospitable places on earth. Athletes continue to push the limits of the human body to discover how much faster they can run, how much longer they can race, and how much higher they can go. Monitoring such feats with constant feedback is only possible through the advent of wearable technology.

Technology in Sports

In American football, advances in technology have allowed players’ safety to increase. Reebok and tech company MC10 have released an innovative technology that measures the force of a hit (or tackle) on a player during a game. The measurement gives a team medic an early indication about whether the player needs examining for a concussion. The sensor-embedded skullcap is designed to withstand huge amounts of pressure, all the while ensuring professional athletes are safe to continue with their game.

Global Positioning System (GPS) trackers can be sewn into athlete uniforms to provide real-time information on a National Football League (NFL) player’s speed, balance, acceleration, and motion. The sensors can report early signs of injuries to soft tissues, giving coaches and medics real-time information to ensure players are substituted before bigger injuries can happen. These sensors and devices must not only be weightless and unobtrusive, but they must also be able to withstand the sweat, motion, impact, and friction that the players undergo during an intense 60-minute game.

But it’s not just the professional athletes who want this kind of information at their fingertips or, in the case of the latest technological breakthrough, on the soles of their feet. Running enthusiasts can now wear sensors in socks and running shoes as the latest way to track their running techniques. When hooked up to a smartphone, the data can show how a runner’s foot strikes the ground, allowing him or her to make adjustments for both speed and physical safety. Being able to capture speed, distance, and ergonomics makes running more of a science than ever before. And by design, these sensors allow runners to also track the impact, sweat, and pounding of their feet as they move on sidewalks, trails, and tracks.

Wearables of the Future

So where will wearable technology take us in the future? Predictions regarding future technology and consumer desires are not always perfectly aligned, but it’s clear that our appetite to monitor, record, and track our every movement is showing no signs of slowing down. In addition to tracking exercise and weight changes, one day, will our training devices convert movement into energy—powering internal sensors to keep our shoes cool or to warm our feet? Could we be wearing contact lenses that allow us to see our calendar and plan our days without opening a laptop? Who knows! But wherever the future of human endeavors takes us, it’s certain that wearables will be coming along for the ride.

Key Takeaways:

  1. While not a harsh environment in the traditional sense, the human body must endure extreme temperatures, shock, and exposure.
  2. The sensitive electronics in wearables must stay within pace with what we put our bodies through, no matter where we are.
  3. Wearables have quickly become ubiquitous—with fitness straps being the most popular device, deluging us with performance, route, and vital statistics during and after our exercise.
  4. As humans, we can survive in some challenging and extreme environments. However, our bodies can also behave like a harsh environment, through our sweat, high motion activities, and skin protection contaminants (such as sun creams and gels) that can affect a wearable device if it is not properly designed.
  5. In some situations, the human body also creates a protective environment for wearables to function: For example, when it allows a battery to continue to operate in an air temperature of -30°C despite a battery’s operational limitations of only -20°C.